1. Field of the Invention
The present invention relates to a liquid crystal display (LCD) device, and more particularly, to a sealant dispensing apparatus of an LCD device.
2. Discussion of the Related Art
Among various ultra-thin flat type display devices, which include a display screen having a thickness of several centimeters, a liquid crystal display (LCD) device can be widely used for notebook computers, monitors, aircraft, and etc. because it has the advantageous characteristics such as low power consumption and portability.
Hereinafter, a related art LCD device will be explained with reference to FIG. 1.
FIG. 1 is a cross sectional view of schematically illustrating a related art LCD device.
As shown in FIG. 1, the related art LCD device includes lower and upper substrates 10 and 20 facing each other with a predetermined interval therebetween, and a liquid crystal layer 30 formed between the lower and upper substrates 10 and 20.
Although not shown, the lower substrate 10 includes gate and data lines crossing each other to define a pixel region; a thin film transistor formed adjacent to a crossing area of the gate and data lines; and a pixel electrode electrically connected with the thin film transistor. Also, the upper substrate 20 includes a light-shielding layer for shielding the gate line, the data line and the thin film transistor from light, a color filter layer formed on the light-shielding layer, and a common electrode formed on the color filter layer.
An alignment layer may be formed on any one or both of the lower and upper substrates 10 and 20. The lower substrate 10 is bonded to the upper substrate 20 by a sealant 40. The liquid crystal layer 30 is formed between the bonded lower and upper substrates 10 and 20.
Methods for forming the sealant 40 are classified into a screen-mask printing method and a sealant dispensing method.
Hereinafter, a screen-mask printing method and a sealant dispensing method according to the related art will be explained with reference to the following drawings.
FIG. 2 is a cross sectional view of illustrating a sealant dispensing process using a screen-mask printing method according to the related art.
First, as illustrated in FIG. 2, a screen mask 60 of a predetermined pattern is positioned above substrates 10 and 20 having an alignment layer 50 formed thereon. After that, a printing roller 70 coated with a sealant 40 is rolled on the screen mask 60, whereby the sealant 40 is coated on the screen mask 60 of the predetermined pattern through gaps 60a in the screen mask 60. That is, the sealant 40 of the predetermined pattern is coated on at least one of the substrates 10 and 20.
However, since the screen-mask printing method necessarily uses a high-priced mask, the manufacturing cost increases. Also, the screen mask may contact the alignment layer, whereby it may cause damage to the alignment layer.
FIG. 3 is a cross sectional view of illustrating a sealant dispensing process using a sealant dispensing method according to the related art.
As illustrated in FIG. 3, a sealant 40 is dispensed on a predetermined portion of a lower substrate 10 or an upper substrate 20 by a sealant dispenser 80. In this case, the process time is long so that the yield is relatively decreased.